Updated kernel packages that fix three security issues, several bugs, andadd two enhancements are now available for Red Hat Enterprise Linux 6.

The Red Hat Security Response Team has rated this update as having moderatesecurity impact. Common Vulnerability Scoring System (CVSS) base scores,which give detailed severity ratings, are available for each vulnerabilityfrom the CVE links in the References section.

The kernel packages contain the Linux kernel, the core of any Linuxoperating system.

This update fixes the following security issues:

* A divide-by-zero flaw was found in the tcp_select_initial_window()function in the Linux kernel's TCP/IP protocol suite implementation. Alocal, unprivileged user could use this flaw to trigger a denial of serviceby calling setsockopt() with certain options. (CVE-2010-4165, Moderate)

* A use-after-free flaw in the mprotect() system call in the Linux kernelcould allow a local, unprivileged user to cause a local denial of service.(CVE-2010-4169, Moderate)

* A flaw was found in the Linux kernel execve() system call implementation.A local, unprivileged user could cause large amounts of memory to beallocated but not visible to the OOM (Out of Memory) killer, triggering adenial of service. (CVE-2010-4243, Moderate)

Red Hat would like to thank Steve Chen for reporting CVE-2010-4165, andBrad Spengler for reporting CVE-2010-4243.

This update also fixes several bugs and adds two enhancements.Documentation for these bug fixes and enhancements will be availableshortly from the Technical Notes document linked to in the Referencessection.

Users should upgrade to these updated packages, which contain backportedpatches to correct these issues, and fix the bugs and add the enhancementsnoted in the Technical Notes. The system must be rebooted for this updateto take effect.

4. Solution:

Before applying this update, make sure all previously-released erratarelevant to your system have been applied.

To install kernel packages manually, use "rpm -ivh [package]". Do notuse "rpm -Uvh" as that will remove the running kernel binaries fromyour system. You may use "rpm -e" to remove old kernels afterdetermining that the new kernel functions properly on your system.